Pump



June 5, 1928. 1,672,422

G. F. NELSON j I PUMP Fiied Oct. so, 1923 2 Sheets-Sheet 1 v F/L'rt/ INVE/VTUE' a E M62 50 June 5, 1928.

G. F. NELSON PUMP 2 Sheets-Sheet 2 Filed Oct. 50, 1923 IN vE/vrm? E R M5. 50W

------e---- --e---- g Arr/$4 Patented June 5, 1928.

4 UNITED STA'ES PATENT OFFICE.

PUMP.

Application filed October 30, 1923. Serial N'o. 671,725.

The present invention relates to improvements in pumps and resides in the pI'0V1Sl OI1 of a small, compact and efficient pump which may be effectively used as a vacuum, blast or pressure pump and is particularly designed for laboratory purposes but however is subject to other uses to which pumps are generally put.

An object of the invention is to provide a pump of the character described which may be constructed of but few and inexpensive parts, will be reliable in operation and which ma be cheaply operated.

nother object of the invention is to provide a pump of the character described in which a high Vacuum may be produced without the employment of a backing up pump and which pump will not be subject to leakage at high or low rotation.

A further object of the invention is to provide a pump of the character described which is of the rotary type and embodies a simple, novel and compact construction, taking into consideration a rotor type of piston operating in a cylinder in conjunction with valves and while submerged in oil, it being unnecessary to employ packing of any sort.

With the above mentioned and other objects in view, the invention consists in the novel construction and combination of parts hereinafter described, illustrated in the accompanying drawings, and set forth in the claims hereto appended, it being understood that various changes in the form, proportion, size and minor details of construction within the scope of the claims may be assorted to without departing from the spirit or sacrificin any of the advantages of the invention.

eferring to the drawing:

Fig. 1 is a perspective view of a pump constructed in accordance with the present invention showing the motor as employed for operating the same.

Fig. 2 represents a front elevation of the pump with the cover plates of the pump housing and pump cylinder removed.

Fig. 3 represents a vertical sectional view of the pump of this invention.

Fig. 4 is a fragmentary view in elevation of the pump and associated parts showing the rotor, piston and associated parts in different positions.

Referring to the embodiment of the invention shown in the drawing, 1 designates a base or support on which the pump 2 of the invention is mounted together with a motor 3, which operates said pump 2 by a belt and pulley drive arrangementgenerally designated 4.

The pump comprises a housing 5 ofrectilinear outline, which is bolted as at 6 to the base 1 and is open on the front side thereof, said front side being covered by a closure plate 7 held in place by fastening elements 8. The plate 7 is provided with an outwardly ofi'set chamber 9 adacent its upper end, which chamber, with the spac in the upper part of the housing, provides .tn air storage or compression compartment within the housing.

Mounted within the housing but spaced from opposite side walls, the front Wall and the upper and lower walls, is a substantially semi-cylindrical pump chamber or casing 10, the open side of which is disposed in uppermost position and is enlarged and beveled on opposite sides providing working faces 11 for valves 12 and 13. Mounted within the casing or chamber 10 is a piston in the form of an elliptical rotor 14. This rotor is carried on a shaft 15 which extends out through a bearing 16 on the rear wall of the housing and has a pulley 17 on its outer end, the pulley being a part of the drive arrangement designated 4. The valves 12 and 13 have rounded inner ends 18 which ride upon the periphery of the rotor 14, whereas the lower sides of the valve curve slightly as at 19 and ride on the seats 11 on the ends of the chamber 10. The seats or faces 11, as well as the curved faces 10, are concentric with the pivotal axes of the valves, said valves being carried on pairs of arms'QO and 21, which are pivoted on a pin 22 extending outwardly from the rear wall of the housing at a point in line with the center of the chamber 10 and rotor. A coiled spring 23-is mounted on the pin and has its ends bent around the arms 20 and 21 as shown at 24, so that said spring will force said valves to yieldingiy engage the periphery of the rotor. The valves are equal in length or width to the width of the rotor which may be, for example, two or more inches wide. These valves by engaging with the rotor and the faces 11 of the housing provide for an effective seal of the pump chamber at the open side thereof, which seal is broken only when the pointed ends of the rotor are moved into a position to engage the rounded ends 18 of the valve, at which time the seal is momentarily broken on the lifting of the valves. The front side of the chamber or casing 10 is closed by'a removable late 25 and the ends of the rotor abutting w1th the closure plate and wall of the chamber 0 posite the closure plate will seal the chamber during the operation of the pump.

The rear wall of the pump chamber is provided with openings 26 and 27 arranged one above the other, the one 26 being in line with the horizontal axis of the pump chamber as close as possible to the semi-cylindrical wall of said chamber. These openings are adapted to be closed by the inner side of the rotor when the pointed or end portions of the rotor are extended horizontally across the pump chamber. The two openings provide a better intaking action inasmuch as were one opening used, the rotor would wipe a film of oil over the opening and interfere with said intaking action. The onenings communicate with a passage 28 formed in an extension 29 on the outer side of the rear wall of the housing, which passage ex-' tends upwardly and terminates in the form of a nipple 30, which nipple is constructed so that a hose may be readily attached thereto. The top wall of the casing is provided with an oil filling openin 31 closed by a plug 32. After the parts 0 the pump are set up for use, oil is poured through this opening so as to partially fill this housing, the level of the oil bein brought up to a point above the upper side of the pump chamber, say up to the level of the pin or pivot 22.

To provide for cooling of the pump, a coil of pipe 33 is fixed to the cover plate and arranged in a arcuate form so that it will extend close to the pump chamber. The ends of the pipe are connected with nipples 34 and 35 on the outer side of the cover plate, one nipple serving as an intake for the water and the other the exhaust whereby a circulation of cold water may be provided to cool the pump.

On the upper side of the extension chamber 9 there is provided an outlet opening 37 into which is secured a fitting 38 which contains a valve 39 having an operating member 40. Upon movement of the operating member, the valve may be openedor closed as desired. On one side of the fitting is a discharge nozzle 41 constructed so that a hose or pipe may be readily connected therewith. Connected with the upper side of the fitting is a gage 42 which indicates the fluid pressure in the housing.

In the operation of the pump, on rotation of the rotor 14, the gas or fluid being treated, is drawn in through the openings 26 and 27 and carried around with the rotor, being trapped between the end portions thereof when the latter are engaged with the arcuate wall of the pump chamber. The vanes the working or valves engaging closely with the chamber and rotor prevent the oil from entering the pump chamber but permit suflicient oil to enter to form lubricating and sealing films on the walls of the chamber and working surface of the rotor and valves. As the rotor advances, say from the position shown in Fig. 2, to the position shown in Fig. 4, turning in a clock-wise direction, the air trapped in the space designated A (Fig. 2), is compressed the compression thereof increasing during the movement of the rotor. When the rotor finally reaches the position shown in Fig. 4, the space designated A in that figure has been reduced and the air compressed therein immediately escapes when the point B of the rotor contacts with the rounded end 18 of the valve 13 allowing the gas to bubble up through the oil and into the storage compression space in the upper portion of the housing. This operation is continuous and it will be seen that the air may be stored and compressed in the chamber provided at the upper end of the housing and may be taken off through the discharge nipple 41, the rate of the take-oil being regulated by the valve 39. When the rotor is in position shown in Fig. 4, the intake ports are closed. This closi g of the ports taking place before the rotor 1s in position shown in said figure in order that during the compression of the air in the space A, should any air escape between the point B and the wall of the chamber and flow into the space 0, (Fig. 4), it will not be lost out through the ports 26 and 27. Immediately on the escapement of the air through the chamber B, the discharge end D, (Fig. 4), of the rotor covers the upper port andbegins to draw in air, gas or whatever fluid is being treated.

It will be seen that the pump of this invention may be utilized as a vacuum pump, blast pump, or as a pressure pump, in either event, accurately, effectively and economically. The simplicity of the construction of i parts of the pump and the ruggedness o the construction with the properly timed special vanes or valves are features of improvements of this invention. The arrangement is such that no packing need be employed for the rotor and this is a feature of considerable advantage.

I claim:

1. A pump adapted to operate while submerged in a body of lubricating fluid, which pump embodies in its construction a substantially semi-cylindrical pump chamber having contiguous intake openings at one end thereof, an elliptical piston rotatable within said chamber and operating to open and close said intake openings, which piston is adapted to have a working fit at its apexes and its opposite ends with the semi-cylindrical wall and the end walls of the chamber and arranged to extend out of said chamber through the opening therein during rotation, tical piston rotatable within said chamber, sealing valves extending for the length of the which piston has a working fit at its apexes chamber along and in sliding engagement and at its opposite ends with the cylindrical with opposite ends of the semi-cylindrical wall and the end walls of the chamber, sealwall thereof and also engaging the periphery ing valves extending for the length of the of said piston on opposite sides of the pistonchamber along and in slidin engagement arms extending convergently from the with o posite ends of the cy indrical wall valves, a support on which said arms are thereo and also engaging the peri hery pivoted and spring means associated with th of the piston on opposite sides of the latter, arms and support for yieldingly holding the means for yieldingly holding said sealing valves in contact with said piston. valves in operative position, said ports be- 2. A pump adapted to be operated while ing arranged one above the other and so that submerged in lubricating fluid, which pump they are successively opened and closed on embodies in its construction a substantially rotation of the piston. cylindrical pump chamber having a pair of intake openings in one end thereof, an ellip- GEORGE F. NELSON. 

